Abstract

Development of a high density optical disk format named DVD was agreed upon last year (1995). The format adopts a 0.6 mm disk to simultaneously use a high numerical aperture (NA) lens and gain tolerance of disk tilt.¹ Because of a Immense popularity of the CD format, it is important to playback the current, widely used Compact Discs (CDs) on the DVD format player. This requires an optical head that can read both conventional 1.2 mm disks and the new 0.6 mm disk. To read both disks with the same optical head, it is necessary to correct spherical aberration, which is caused by the difference in disk thickness.

© 1996 Optical Society of America